National Benchmark 5B:By the end of the 12th grade, students should know that:Gene mutations can be caused by such things as radiation and chemicals. When they occur in sex cells, the mutations can be passed on to offspring; if they occur in other cells, they can be passed on to descendant cells only. The experiences an organism has during its lifetime can affect its offspring only if the genes in its own sex cells are changed by the experience.
What does the standard mean? (What are its component subtopics, processes, etc.?)
DNA provides for both the continuity of traits from one generation to the next and the variation that in time can lead to differences within a species and to entirely new species
Variation among individuals may be due to genetic and/or environmental factors.
Things such as radiation and chemicals can cause changes in DNA
These changes can either be heritable or not heritable
Heredity is the transfer of characteristics from parent to offspring through their genes.
In order to be heritable by offspring, the change in DNA has to occur in the sex cells
What do students need to understand BEFORE you can address these topics?
Mitosis versus meiosis
The function of DNA
Components of DNA
What a mutation is
Sexual Reproduction
What prior (mis)understandings are students likely to have about these topics?
Mutations are all harmful or "bad"
All mutations can or will be passed on to offspring
Radiation and chemicals are the only things that can cause mutations
Students do not distinguish between sexual and asexual reproduction.
National Benchmark 5B: By the end of the 12th grade, students should know that: Gene mutations can be caused by such things as radiation and chemicals. When they occur in sex cells, the mutations can be passed on to offspring; if they occur in other cells, they can be passed on to descendant cells only. The experiences an organism has during its lifetime can affect its offspring only if the genes in its own sex cells are changed by the experience.